Oncogene addiction to GNAS in GNASR201 mutant tumors

• Published in: Oncogene Vol. 41; no. 35; pp. 4159 - 4168
• Main Authors: More, Aditya, Ito, Ichiaki, Haridas, Valsala, Chowdhury, Saikat, Gu, Yue, Dickson, Princess, Fowlkes, Natalie, Shen, John Paul
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 26.08.2022; Nature Publishing Group
• Subjects: 13/1; 13/100; 13/106; 13/51; 14/105; 14/5; 14/63; 38/23; 38/39; 38/77; 38/91; 42/109; 42/41; 59/5; 631/67/1504/1885; 631/67/327; 631/67/395; 64/60; Addictions; Animal models; Apoptosis; Cell Biology; Colorectal cancer; Colorectal carcinoma; Cyclic AMP; Human Genetics; Internal Medicine; Medicine; Medicine & Public Health; Mutants; Mutation; Oncogenes; Oncology; Organoids; Pancreatic cancer; Peritoneum; Phosphorylation; Protein kinase A; Therapeutic targets; Tumorigenesis; Tumors; Wnt protein; β-Catenin
• DOI: 10.1038/s41388-022-02388-6
• ISSN: 0950-9232; 1476-5594

The GNAS R201 gain-of-function mutation is the single most frequent cancer-causing mutation across all heterotrimeric G proteins, driving oncogenesis in various low-grade/benign gastrointestinal and pancreatic tumors. In this study, we investigated the role of GNAS and its product Gαs in tumor progression using peritoneal models of colorectal cancer (CRC). G NAS was knocked out in multiple CRC cell lines harboring GNAS R201C/H mutations (KM12, SNU175, SKCO1), leading to decreased cell-growth in 2D and 3D organoid models. Nude mice were peritoneally injected with GNAS -knockout KM12 cells, leading to a decrease in tumor growth and drastically improved survival at 7 weeks. Supporting these findings, GNAS overexpression in LS174T cells led to increased cell-growth in 2D and 3D organoid models, and increased tumor growth in PDX mouse models. GNAS knockout decreased levels of cyclic AMP in KM12 cells, and molecular profiling identified phosphorylation of β-catenin and activation of its targets as critical downstream effects of mutant GNAS signaling. Supporting these findings, chemical inhibition of both PKA and β-catenin reduced growth of GNAS mutant organoids. Our findings demonstrate oncogene addiction to GNAS in peritoneal models of GNAS R201C/H tumors, which signal through the cAMP/PKA and Wnt/β-catenin pathways. Thus, GNAS and its downstream mediators are promising therapeutic targets for GNAS mutant tumors.